High-to low-pressure converter



NOV. 5, 1946. ROCKWELL 2,410,750

HIGH-TO-LOW PRES SURE CONVERTER Original Filed Jan. 4, 1940 2 Sheets-Sheet l 1 a" Y a A 6%.] 275 5 ATTOR EY Nov. 5, 1946'. E. A. ROCKWELL HIGH-TO-L OW PRESSURE CONVERTER 2 Sheets-Sheet 2 Original Filed Jan. 4, i940 SQN TOR

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2,410,150 mom in LGWFPRESSURE convenin Edward A. Rockwell, Cleveland, Ohio, assignor to The New Britain Machine fiompany, New Britain, Comm, a, corporation of Connecticut Original eppllcutionlanuery 4, 1940, Serial No. 312,356, new Putent No. 2,331,800, dated October 12, 1943. Divided and this application Februany 17, 1943, Serial No. 476,248., lln Canada December 30, 1M5

13 Claims. (Cl. .6054.6)

l 2 My invention relates particularly to an appamodulated high pressure to said brakes for oblBLtHS designed for controlling the application of taining the braking force. In this form of my power for the operation of diiierent parts or acinvention I have provided a reserve tank i havcessories of automotive vehicles, as, for example, ing an outlet port 5 leading to a supply pipe 6. automobiles,'aeroplanes, railroad cars, mine loco- 5 This supply pipe 6 communicates with a spillmotlves, eilcback tank 2% which has a vent pipe 2% leading This application is a division of my co-pending up through the tank I beneath the cap 2 thereon.

application Ser. No. 312,356, died January 4, 1940, The vent pipe 2st opens from the top of the spillupon System for controlling the application of back tank 258. The pipe 6. however, continues power, Patent No. 2,331,800, granted October 12, i0 inwardly into the latter to communicate with 1943, t the inlet side of a rotary pump 2% which may be The objector my invention is to provide asysa gear pump and which is driven by an electric tem whereby the different parts of automotive motor 259. This pump 25!) is connected so as to vehicles may be operated in an advantageous deliver, by a port, the high pressure liquid to an manner so as to maintain adequate control over accumulator 253 constructed with the same parts the slime at times- Anflther O j c 15 D as described in connection with the accumulator vide an apparatus of this character, in accord- H, in said Patent No. 2,331,800, and has the same ance with which the part to be operated maybe circuit connections to the electric motor as there moved into position initially by means of a fluid described, except that a pressure otabout 1500" applied at one pressure, and thereafter operated lbs. pensquare inch is capable of being supplied to Cause t Performance Of W by said p y thereby. The high pressure liquid thus accumufiuid at another P s r hi eing accomlated in the accumulator 253 is delivered by a he f de e by various d fierentlals bepipe 2st from a passageway zeta therein having tWeBn the pressures filp d r m n aid part 1 a. check valve to a regulator valve 255 for and the manual or actuating pressures utilized maintaining a, definite pressure, which has 8. 001130111118 th P es 50 pp d- My i valve structuresubstaintially the same as in the ventlon is adapted to be applied, not only for the valve lt'l in said Patent No. 2,331,800. This regoperation of heavy-duty parts, as, for instance, ulator valve 255 is connected by a port 265 to the on heavy trucks, requiring a, considerable volume pipe 256 from which the valve receives thepresof pressure fluid for the operation of the same u liquid delivered by the accumulator 253. t also r the p i n f l i y light par The low pressure, or exhaust liquid, leave the on aeroplanes and other automotive vehicles, valve 255 by a. pipe 268110 returnto the spill-back such, for instance, as light trucks, etc. Still antank 2%. In this valve structure the valve I52, other j c is 13 pr vi e an u l ad valv I53 is normally closed by the spring 260a and the Another object is to provide aconverter valve. valve ass, 568 normally open and the compres-' u th o j of my nv nti l a p ar fr m sion of the spring ztta. normally maintains the the detailed description of the some hereinafter. pressure of the liquid at a. given desired pressure.

Whi my inv n n i apable of embodiment When this pressure is exceeded the said two in m y difierent fl 'm I h ve S Wn ly valves open and close, respectively, and the extain embodiments thereof m the accompanying 40 must liquid passes out by the valve 852, I53. drawings in This construction produces a. regulated pressur Fig. 1 is an elevation of a form of the system of approximately 1000 lbs. per square inch, which involving the manual application of high presis delivered by the said valve 255 through a port sure to apply thereby a modulated low and then 26'? to a pipe 266 which then conveys it to .a, high a high Pressure; pressure ort 269 of a modulator valve 210, and

Fi 21 a P V w f a ta l er vf. with which is constructed substantially the same as parts in section on line 22 of Fig. 1; the modulator valve 831 in said Patent No. Fig. 3 is .a. transverse section of a converter 2,331,800 except in this instance inside the spring f m hi h to lo pressure use i i 1; and In there is a light spring 21 la, to normally keep F18. 4 is a diagramma ic repr e i the the valve I52 open. On the side of said modulr uit F s. 1'- lator valve 210 the pipe 268 has a connecti n The form of my invention shown in Figs. 1 and whichconveys the high pressure liquid by a. pipe 2 d d for heavy-duty Operation d may 212-110 the high pressure port 213 of a hand-opbe used, for example, in connection with the operated modulator valve 2'" provided with a. discretion of mine locomotives 'or railway cars. 55 charge pipe 2142 leading to the reserve tank I, This form of my invention is designed, furtherand having a handle #15 to operate the same, all more, to modulate a. regulated high pressure to of which is constructed exactly like the said modproduce a modulated low pressure for bringing ulator valve I 31. This handle 215 thus enables the brakes into position preparatory to applying modulated high pressure to be delivered from the braking. force and thereafter to apply av a. port 216 thereof by a pipe ill to a delayed-action hydraulic modulator controlling device 218 constructed with a strong spring 28I therein whichoperates the said modulator valve 218 hydraulically according to the operation of the hand lever 215, but only after the brake shoes have been moved up into position. Thus, aiter the brakes have been moved up into braking po- 211, for preliminarily moving the brakes into p- 'sition, passes by a pipe 282 to a hydraulic .device 288 constructed the same asthe device 218 except that'in this instance a light spring "I is used,

and which in turn operates a modulator valve 284 4 by said valve from the pipe 212 is applied through the pipe 282 to the light spring hydraulic control 288 so as to modulatingly release the high pres- ,sure fluidreceived from the pipe 288 through the pipe 281 to the high pressure end of the highto-low pressure converter 288 so as to thereby force out of the low pressure side 01' the same, through the pipe 289, a low pressure liquid which passes directly through the modulator valve 218 because the valve 152 is kept open at this stage by the strong spring control 218, 28I, this low pressure liquid being thus delivered by the pipe 288 to the brakes to move the brake shoes initially 218, a portion of this same liquid from thepipe constructed the same as the modulator Valves T previously described, as, for instance, said modulator valve I81. In this instance the high pressure liquid to be modulated by the hydraulic ele-,

ment 288 is receivedby 'a pipe 288 from the other side of the accumulator 258 and is thus received in a high pressure port 288 of the modulator valve 284 from which the modulated. pressure liquid is delivered by a pipe 281 to the high pressure side of a high-tc-low pressure converter 288. This is comprised of a small cylinder 288a, having a normally closed air bleeder 2881), in which there is a piston 288c with a checkon unloader valve,

288d. v The check valve 288d isin a passageway 288a leading to a low pressure large cylinder 2 88!, having a piston 288a, and provided with an air sure supplied through the port 298, due to the strong spring. 28I keeping the valve I82 open in the initial operation of the brakes,.permits the low pressure fluid to pass between the valve I82 and its seat and thence to the pipe 288 for the movement of the brake shoes up to tne braking position. When the pressure in the pipe 288 has been applied to such an'extent as to move the brake shoes into position, the increase in pressure within the pipe 211 will seat the valve I52 in the modulator valve 218 to permit the entry of'high' pressure liquid by the valve I81, thus supplying the high pressure liquid through the pipe 288 to apply the braking effect as previously described. The exhaust flow of liquid from the modulator valve 218 is received in the pipe 288.

In this way a relatively high pressure may be used for applying a comparatively low pressure for the initial seating 01' the brakes, as, for instance, on mine locomotives or railway cars, .while high pressure liquid is applied thereafter to the brakes to obtain the desired braking force.

In the form of my invention shown in Figs. 1, 2, 3 and 4, there is utilized a-relatively highpressure which initially brings a relatively low pressure into action for setting the brakes into position,-after which a modulated high pressure is applied for applying the braking force. In this instance, when the hand control modulator valve 214 is operated the high pressure liquid received 'bleeder 2887. An air filter 288i is on the cylinder into position. As the pressure applied increases in the pipe 211 this brings about no increased action on the part of the control 288 but acts to overcome the strong spring-2M in the control 218, thus closing the valve I52 and opening. the valve I81 in the modulator valve 218, and thus supplying a modulated high pressure liquid through the pipe 288 to apply the braking force on the brake shoes. In this way any desired increments of increasing pressure, initially low and thereafter high pressure, can be applied for the operation of the brakes. In the oil modulation of the valve 218 the liquid flows in the reverse direction in the pipe 288, and from the modulator valve 214 back to the reserve tank 'I through the pipe 214a and from the modulator valve 284 through the pipe 2881' back to the spillback tank 248.

. While I have described my invention above in 2 detail I wish it to be understood that many changes may be made therein without departing from the spirit of the same. I

Iclaim: 1. A pressure transformer comprising a hydraulic inlet,-a hydraulic-outlet line, a manually in the same direction with the inlet and mounted in a passageway extending through said pistons to prevent by seating the flow of fluid from the inlet through said passageway and adapted to dis charge the liquid from said line to said reservoir, operatively connected to the manually controlled -member.

a movable member, having a small piston and va large piston connected'together, with the large piston nearer to said line, said member being controllable manually for iorcingliquid therethrough, cylinders for said pistons, resilient means which moves said member away from said line when not being controlled manually, a source of supply of hydraulic liquid for said member, and a valve to normally cut ofl! the liquid from the source of supply to saidline and adapted to dis-' to discharge the liquid from said line to said source of supply, mounted on the movable member.

4. A construction, comprising a hydraulic line, a movable member, having a small piston and a large piston connected together, with the large piston nearer to said line, said member being controllable manually for forcing liquid therethrough, cylinders for said pistons, resilient means which moves said member away from said line when not being controlled manually, a source of supply of hydraulicliquid for said member, and a valve to normally cut oil the liquid from the source of supply to said line and adapted to dischargethe liquid from said line to said source of supply, mounted on the movable member.

5. A low pressure converter comprisin a small cylinder, 9, large cylinder, pistons connected together to form a double piston to operate in said cylinders, resilient means which moves the pistons towards the small cylinder, a liquid supply inlet and outlet on the smal1 cylinder at one end of the double piston, a valve movable with said pistons adapted to close in the same direction with said inlet of liquid, and an inlet for liquid in the large cylinder at the other end of the double piston, which has a passageway containing said valve passing through both said pistons.

6. A low pressure converter comprising a small cylinder, a large cylinder, pistons connected to-.

gether to form a double piston adapted to operate in said cylinders, resilient means which moves the pistons towards the small -cylinder, a liquid supply inlet and outlet on the small cylinder at one end of the double piston, a valve movable with said pistons, adapted to close in the same direction with said inlet-of liquid, an inlet for liquid in the large cylinder at the other end of the double piston, and a breather opening in the large cylinder, having an air filter communicating therewith, located between the two pistons which have a passageway containing said valve passing through both said pistons.

7. A pressure transformer comprising a hydraulic line, a manually controlled member comprising a small and a large piston connected together for forcing liquid therethrough with the large piston nearer to the hydraulic, line, resilient means which moves the pistons away from said line, a breather chamber between the pistons, a

supply reservoir for said member and an unloader valve mounted in a passageway extending through said pistons and adapted to discharge the 50 liquid from said line to said reservoir, operatively connected to the manually controlled member.

8. A construction, comprising a hydraulic line,

-a' movable member controllable manually for forcing liquid therethrough, a cylinder for the movable member, a source of supply of hydraulic liquid for said member, and a valve to normally cut ofi the liquid from the sources of supply to said line and adapted to discharge the liquid from said line to said source of supply, oper atively connected to the movable member, said movable member comprising small and large pistons with the large piston nearer to the hydraulic line, resilient means which moves the pistons away from said line, and an intermediate breather chamber, said movable member being provided with a communicating passagewaybetween the same containing said valve.

9. A construction, comprising a hydraulic line,

through, cylinders for said pistons, resilient means which moves said member away from said line when not being controlled manually, a source of supply of hydraulic liquid for said member, and a valve to normally cut off the liquid from the source of supply to said line and adapted to discharge the liquid from said line to said source of supply, operatively connected to the movable member, said pistons having a passageway containing said valve passing through both said pistons.

10; A construction, comprising a hydraulic line, a movable member controllable manually for forcing liquid therethrough, a cylinder for. the movable member, a source of supply of hydraulic liquid for said member, and a valve to normally cut off the liquid from the source of supply to 'said line and adapted to discharge the liquid from said line to said source of supply, mounted on the movable member,. said movable member comprising small and large pistons with the large piston nearer to the hydraulic line, resilient means which moves the pistons away from said line, and an intermediate breather chamber, said movable member being provided with a communicating passageway between the same containing said valve,

11. A construction, comprising a hydraulic line, a movable member, having a small piston and a large piston connected together, with the large piston nearer to said line, said member being controllable manually for forcing liquid therethrough, cylinders for said pistons, resilient means which moves said member away from said line when not being controlled manually, a source of supply of hydraulic liquid for said member, and a valve to normally cut off the liquid from the source of supply to said line and adapted to discharge the liquid from said line to said source of supply, mounted on the movable member, said pistons having a passageway containing said valve passing through both said pistons.

12. A low pressure converter comprising a small cylinder, a large cylinder, said converter being provided with a breather chamber, pistons connected together to form a double piston to operate in said cylinders, resilient means which moves the pistons towards the small cylinder, a liquid supply inlet and outlet on the small cylinder at one end of the double piston, a valve, movable with said pistons, adapted to close in the same direction with said inlet of liquid and 13. A low pressure'converter comprising a small cylinder, a large cylinder, said converter being provided with a breather chamber, pistons connected together to form a double piston to operate in said cylinders, resilient means which moves the pistons towards the small cylinder, a liquid supply inlet and outlet on the small cylinder at one end of the double piston, a valve, movable with said pistons, adapted to close in the same direction with said inlet of liquid, an inlet for liquid on the large cylinder at the other end of the double piston, and a breather opening for the breather chamber in the large cylinder located between the two pistons, said double piston having a passageway containing said valve i and passing through both said pistons.

EDWARD A. ROCKWELL. 

